Trehalose sensitivity in Drosophila correlates with mutations in and expression of the gustatory receptor gene Gr5a
Trehalose sensitivity in Drosophila correlates with mutations in and expression of the gustatory receptor gene Gr5a
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DOI：
10.1016/s0960-9822(01)00450-x
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发表时间：
2001-09-18
期刊：
影响因子：
9.2
通讯作者：
Isono, K
中科院分区：
文献类型：
--
作者：
Ueno, K;Ohta, M;Isono, K
果蝇味觉基因Tre位于远端X染色体上，并控制对糖子集的味觉敏感性[1，2]。Tre基因座附近的两个相邻的七跨膜结构域基因是Tre的候选基因。一个（CG 3171）编码视紫红质家族G蛋白受体[3，4]，另一个（Gr 5a）是编码推定味觉受体的化学感受基因家族的成员[5-7]。我们进行了分子分析的突变Tre阐明其参与味觉表型。在这里，我们表明，由P元件介导的基因组缺失诱导的Tre突变破坏了Gr 5a基因的组织和Gr 5a mRNA的表达，而CG 3171基因或其表达的破坏并不总是与Tre突变相关。在具有自发突变Tre（01）的果蝇中，CG 3171和Gr 5a mRNA都被转录。在不同菌株中比较这两个候选基因的编码序列。CG 3171中共有3个导致氨基酸变化的多态性位点与味觉表型无关。在Gr 5a的四个非同义位点中，一个单核苷酸多态性导致预测的第二胞内环中的AIa 218 Thr取代与Tre共分离（01）。总之，突变分析支持Gr 5a与Tre等位。
Drosophila taste gene Tre is located on the distal X chromosome and controls gustatory sensitivity to a subset of sugars [1, 2]. Two adjacent, seven-transmembrane domain genes near the Tre locus are candidate genes for Tre. One (CG3171) encodes a rhodopsin family G protein receptor [3, 4], and the other (Gr5a) is a member of a chemosensory gene family encoding a putative gustatory receptor [5-7]. We carried out molecular analyses of mutations in Tre to elucidate their involvement in the gustatory phenotype. Here, we show that Tre mutations induced by P element-mediated genomic deletions disrupt Gr5a gene organization and the expression of Gr5a mRNA, while disruption of the CG3171 gene or its expression was not always associated with mutations in Tre. In flies with the spontaneous mutation Tre(01), both CG3171 and Gr5a mRNAs are transcribed. Coding sequences of these two candidate genes were compared among various strains. A total of three polymorphic sites leading to amino acid changes in CG3171 were not correlated with the gustatory phenotype. Among four nonsynonymous sites in Gr5a, a single nucleotide polymorphism leading to an AIa218Thr substitution in the predicted second intracellular loop cosegregated with Tre(01). Taken together, the mutation analyses support that Gr5a is allelic to Tre.